I am running the latest version under win7-64, and I have experienced several sudden crashes. If I recall, the last one occurred while inserting a library object. I saved the Windows crash reports, if that can be of any use...QCAD did not offer a bak file upon restart but I found a "~myfile.dxf" in the working directory. I wonder if anyone has experienced a similar behavior?

Hi Clive,I do not believe it is related to the block itself, as upon restarting I inserted it with no problem, it was just a simple hex bolt head top view...I tried to read the crash report generated by Windows, but it does not make much sense to me!

it can't help you in this case but you are running an additional Backup Software? I use one for cases like this with a File History. What means I have always a Drawing History of at least 5 preparatory stages - regardless when I did them! Usually I need only the last one - but you never know!